JP3329244B2 - Blast furnace operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blast furnace operating method for stabilizing a furnace condition of a blast furnace by using a result obtained by processing an image obtained by photographing a furnace opening with a night vision camera.

[0002]

2. Description of the Related Art High pulverized coal injection from tuyeres (high PC
In the current blast furnace operation, where the ore / coke ratio (hereinafter referred to as “O / C”) has been improved by the operation, the importance of the central gas flow has been recognized in order to secure a stable furnace condition. . That is, it is empirically known that, when the center gas flow is attenuated, the occurrence of slip and the fluctuation of the blowing pressure increase, leading to deterioration of the furnace condition such as poor tapping residue. Conversely, unnecessarily enhancing the central gas flow increases the heat loss at the furnace top, leading to an increase in fuel ratio. Therefore, in order to efficiently maintain a stable reactor condition, it is necessary to secure a stable center gas flow.

[0003]

Conventionally, the central gas flow was grasped by temperature / gas component analysis using a horizontal probe. However, in this method, the strength of the central gas flow, that is, the temperature difference was determined. , The size, that is, the central flow area, was difficult to simultaneously represent as one index.

In Japanese Patent Application Laid-Open No. Hei 3-17211 and Materials and Processes [9 (1996), p. 183], a method of performing furnace condition analysis by photographing a furnace opening with a night-vision camera and processing the image is performed. However, the former uses the area of the flowing part and the bright part determined by the luminance difference, and the latter uses the analysis result of the one-dimensional area obtained by image processing the line area in the image by the night vision camera. However, it is not a numerical value that indicates the “strength” and “width” of the central gas flow at the same time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and performs image processing of a night-vision camera image provided at a blast furnace opening for proper management of a center gas flow. , So that the central gas flow is within the appropriate range,
It is an object of the present invention to provide a blast furnace operating method capable of maintaining a stable furnace condition by adjusting a radial gas flow distribution.

[0006]

In order to achieve the above-mentioned object, a method for operating a blast furnace according to the present invention is based on an image of a predetermined area centered on the axis of the blast furnace taken by a night-vision camera. The two-dimensional image mass of the central luminance portion is determined, and the gas flow distribution in the radial direction is adjusted so that the two-dimensional image mass falls within an appropriate range. By doing so, the center gas flow falls within an appropriate range, and a stable furnace state can be maintained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The blast furnace operating method of the present invention is provided with a night-vision camera at the mouth of a blast furnace, and taking an image of a predetermined area around the axis of the blast furnace with the night-vision camera. Is used to determine the two-dimensional image mass of the central luminance portion of the stock line, and adjust the gas flow distribution in the radial direction so that the two-dimensional image mass falls within an appropriate range.

In the blast furnace operating method according to the present invention, an image of a predetermined area around the axis of the blast furnace is photographed by a night-vision camera provided at the blast furnace furnace opening. Then, based on the captured image, the computing unit computes, for example, the mass of the two-dimensional image of this image from the total number of high-luminance pixels in the two-dimensional region considered to be the central gas flow region in this image, and the computation result Is output.

From the result, the relationship between the image mass of the central gas flow obtained in advance and the data indicating the deterioration of the furnace condition such as slip and wind pressure fluctuation, it is determined that the current central gas flow is insufficient. If so, strengthen the central gas flow. On the other hand, if it is determined that the central gas flow is more than necessary, the central gas flow is suppressed. By doing so, the furnace top heat loss can be reduced and the fuel ratio can be reduced.

In the present invention, the method of adjusting the center gas flow is not particularly limited. For example, in the bellless blast furnace, the swirling chute pattern is changed. In the bell blast furnace, the movable armor is adjusted or the raw material particle size is changed. In a blast furnace that can be filled, the adjustment is performed by adjusting the amount of central coke.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A blast furnace operating method according to the present invention will be described below with reference to an embodiment shown in the accompanying drawings. FIG. 1 is a schematic diagram of an image processing unit used in the blast furnace operating method of the present invention, and FIG. 2 is a schematic diagram showing an image mass determination method of the image processing unit used in the blast furnace operating method of the present invention.

In FIGS. 1 and 2, reference numeral 1 denotes a night vision camera provided at a furnace port, and an image of a predetermined area centered on the axis of the blast furnace taken by the night vision camera 1 having a fixed field of view and a stop. 2 (a)] is sent to the arithmetic processing unit 2, where the mass of the two-dimensional image in the high-luminance part is determined.
In FIG. 1, reference numeral 4 denotes a video tape recorder for recording images captured by the night-vision camera 1, and reference numeral 5 denotes a data logger for storing images processed by the arithmetic processing unit 2.

The method of determining the mass of a two-dimensional image in a high-luminance part in the arithmetic processing unit 2 is described, for example, in FIG.
As shown in FIG. 2, a method in which a region A where the center gas flow is likely to be specified is specified in advance, and as shown in FIG. Other methods may be used as long as the two-dimensional image mass of the luminance portion can be determined. However, the condition is that the image is processed in two dimensions. In FIG. 2B, B indicates a raw material region, and 3 indicates a blast furnace.

The relationship between the two-dimensional image mass of the high-luminance portion determined by the arithmetic processing unit 2, the two-dimensional image mass of the center gas flow obtained in advance, and data indicating deterioration of the furnace condition such as slip and wind pressure fluctuation is shown. Based on this, it is determined whether the current center gas flow is appropriate, insufficient, or too strong.

If it is determined that the current center gas flow is appropriate, the current operation is continued. On the other hand, if it is determined that the current center gas flow is insufficient, or conversely, if it is determined that more Then, in order to suppress the center gas flow, for example, in the case of a bellless blast furnace, the turning chute pattern is changed.

The capacity is 2700 m ³ , the furnace diameter is 8 m, and the reference mass of the mass of the two-dimensional image of the high luminance portion is 2500 to 3000.
FIG. 3 shows the relationship between the two-dimensional image mass obtained as described above and the wind pressure fluctuation using the blast furnace described above, and FIG. 4 shows the relationship with the slip. FIG. 5 shows the relationship with the furnace top heat loss.
FIG. 6 shows the relationship with the fuel ratio.

3 and 4 that the two-dimensional image mass is 25
When it is less than 00, both wind pressure fluctuation and slip increase,
On the contrary, it can be seen from FIGS. 5 and 6 that both the furnace top heat loss and the fuel ratio increase as the two-dimensional image mass increases.

From the above, while ensuring a stable furnace condition,
To reduce the fuel ratio, the value of the two-dimensional image mass must be 2500
From the above, it can be seen that the central gas flow should be adjusted so as to be as close as possible to 2500. The points in FIGS. 3 to 6 are the adaptation results of the method of the present invention in actual operation.

At the point A where the two-dimensional image mass is about 1000, the number of slips was as large as eight times a day (see FIG. 4), and the furnace condition was unstable. The result of enhancing the central gas flow from the state of the point A until the two-dimensional image mass becomes about 2700 is a point B. As a result, the number of slips is 3 per day
Times (see FIG. 4) and the wind pressure fluctuation also decreased (see FIG. 3).

A point C where the two-dimensional image mass is about 3400
Point D shows that the central gas flow was suppressed from about to 2500. As a result, as shown in FIG. 5, the heat loss at the furnace top was reduced by about 30 Mcal / pt, and as shown in FIG. In addition, the fuel ratio was reduced by about 5 kg / pt.

The unit of the two-dimensional image mass is dimensionless.
Since the value varies depending on the field of view of the night-vision camera 1, the aperture, and the like, the value of 2500 of the two-dimensional image mass is suitable only in the present embodiment and is not an absolute value. .

[0022]

As described above, according to the present invention,
Since the measurement of the center gas flow in the blast furnace can be grasped more accurately than in the case where a conventional sonde is used, a stable furnace condition can be secured and the fuel ratio can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image processing unit used in a blast furnace operating method of the present invention.

FIGS. 2A and 2B are schematic diagrams showing a two-dimensional image mass determination method of an image processing unit used in the blast furnace operation method of the present invention, wherein FIG. 2A shows an original image of a furnace port by a night vision camera, and FIG. FIG. 3C is a diagram showing designation of an area, and FIG. 3C is an explanatory diagram of a method for determining a two-dimensional image mass based on a grayscale profile image.

FIG. 3 is a diagram showing a relationship between a two-dimensional image mass obtained using a blast furnace and a wind pressure fluctuation.

FIG. 4 is a diagram illustrating a relationship between a two-dimensional image mass obtained using a blast furnace and slip.

FIG. 5 is a diagram showing a relationship between a two-dimensional image mass obtained by using a blast furnace and a furnace top heat loss.

FIG. 6 is a diagram showing a relationship between a two-dimensional image mass obtained by using a blast furnace and a fuel ratio.

[Explanation of symbols]

 Reference Signs List 1 night vision camera 2 arithmetic processing unit 3 blast furnace A gas flow area

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C21B 5/00 C21B 7/24

Claims (1)

(57) [Claims] 1. A night vision camera is provided at an opening of a blast furnace, an image of a predetermined area centered on the axis of the blast furnace is taken by the night vision camera, and a central brightness portion of a stock line is taken based on the taken image. A blast furnace operating method comprising: obtaining a two-dimensional image mass; and adjusting a radial gas flow distribution such that the two-dimensional image mass falls within an appropriate range.